This application claims the priority of German application 197 32 096.1, filed in Germany on Jul. 25, 1997, the disclosure of which is (are) expressly incorporated by reference herein.
The present invention relates to an arrangement for sealing an opening of a rotor housing under low pressure, and through which opening a shaft of a spinning rotor extends, said shaft being supported outside of the rotor housing, said arrangement comprising a sealing disk arranged floating relative to the opening and disposed on a bearing surface, which sealing disk comprises a through bore hole having a narrow tolerance in relation to the shaft, the diameter of the through bore hole being smaller than the diameter of the opening.
In the case of an arrangement of this type (U.S. Pat. No. 4,383,406), the size of the opening and the surface of the sealing ring affected by the low pressure must be structurally adapted to the installed low pressure in order to effect the desired action. In the case of such an arrangement, the design engineer has to work within a very narrow framework. The sealing ring alters its position when no effective low pressure is present, for example when the lid which closes the rotor housing is opened or when the machine is stopped. According to the prevailing conditions in the spinning mill, this may often be the case. When the low pressure is again generated, the sealing disk has to be readjusted, whereby it comes into sliding contact with the shaft of the spanning rotor.
It is an object of the present invention to create an arrangement of the above mentioned type comprising a floating sealing disk, which is independent of the vacuum required for spinning in the spinning unit.
This object has been achieved in accordance with the present invention in that the sealing disk is pressed, counteracting the effect of the low pressure, against the bearing surface by means of at least one spring element.
By means of the application of the spring element, there is complete independence from the installed low pressure. As the effect of the spring element is directed against the action of the low pressure, a bearing surface can be easily structurally realized which keeps the sealing disk in its position, when for example the machine is stopped and no effective low pressure is present, or when the spinning rotor--for example when a known supporting disk bearing is used--is taken out of the open end spinning aggregate through the opening towards the service side.
The spring element is advantageously designed as a type of disk spring, which is supported on the one side on a supporting surface of the rotor housing and on the other side on the bearing surface. When the disk spring hereby takes the form of a so-called zigzag spring, the resilient ring is disposed alternately on the supporting surface and on the bearing surface, as seen from a circumferential direction.
Assembly can be carried out in a particularly simple way when the bearing surface is arranged to a ring-like component, which preferably can be clipped onto a holding notch of the rotor housing.
The sealing effect can be improved when the sealing disk is disposed adjacent to a collar pressed onto the shaft and when the sealing disk and the collar form a labyrinth seal. The pressed-on collar is present in any case in known spinning rotors in which a rotor cup is pressed onto the shaft. Thus a labyrinth-type, additional deflection arises, which hinders the entry of inleaked air into the rotor housing.
In order to effect a reaction against the unavoidable wear of the sealing disk at the through bore hole, the sealing disk is provided at the through bore hole for this purpose with a thicker wall.
These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawing.